A method to determine minimum design metal temperature of pressure vessels made from ferritic steel by Master Curve approach

•We found the distinguish the low temperature fracture toughness of steel well.•Material with similar low temperature toughness can’t be divided into the same impact exemption curve in ASME.•Seven minimum design metal temperature (MDMT) curves are proposed based on different yield strengths and seven assumed reference temperature, T0MC.•The MDMT can be determined when the reference temperature and yield strength of steel are measured.•SA508-3 and Q345R are used to illustrate the applicability of the MDMT curves for pressure vessels made from ferritic steel.